Rotary seal for compressors and the like



Jan. 12, 1937. G. NANos ET AL 2,067,540

ROTARY SEAL FOR COMPRESSORS AND THE LIKE Filed April 15, 195s lll/1 AT ORNCY Patented Jan. l2, 1937` PATENT OFFICE ROTARY SEAL FOR COMPRESSORS AND THE LIKE George Nanos and Richard R, Blythe, New York,

N. Y.; said Nanos assgnor to said Blythe Application April 13, ,1936, serial No. 74,006

3 claims. (ci. 286-7) The principal object of the invention is to pro- Vide a rotary seal which Will act immediately on placement in the unit and will continue to hold pressure evenunder long Wear.

One of the troubles with rotary seals as made in standard practice is thatthey require a run in period before they seat themselves perfectly enough to hold the pressure. Another defect is that after'long Wear the parts are so constructed that the wearing surfaces cut, the harder into the softer, and leave a burr or chip at the edge l5 which impairs its proper function. Another serious difficulty arises from the fact that in installing the standard seal now used in a compressor the workman in the factory or the repairman is not careful or accurate enough in his work to assure absolute alignment of the parts and binding of the contact elements increases the wearin time.

The design disclosed in the accompanying drawing provides self-aligning features which permit the parts to act immediately and to produce a perfect sealing action after a very short run or operation. This feature also greatly increases the life of the seal.

The details of construction which accomplish these ends are better disclosed by reference to the drawing, in which,

Fig. 1 is a vertical section taken thru the end of la compressor along the center line of the shaft, and bearing to be sealed.

35 Fig. 2 is a vertical section of the cup part of the seal.

Fig. 3 is a vertical section of the bushing which bears against the cup and forms the seal.

Fig. 4 is a vertical section of the washer which seals the cup to the shaft.

Similar reference numerals refer to similar parts thruout the drawing.

A compressor frame I has an extended flange housing 2 thru which` the shaft3 projects. The shaft 3 passes thru bearing 5 in the housing and is then preferably reduced to form the shoulder 4. The housing 2 has a cavity 6 into which the seal parts are assembled. The cavity 6 is closed by a relatively thin plate 1 which is held in place by bolts a and sealed by gasket s. This plate 1 has a hole la thru which a relatively soft bushing I0 extends. This bushing has a ange Illa and a convex face IIlb. A relatively heavy plate II, held also by bolts 8 forces against the ange Illa of the bushing lo and holds it tightly in piace against plate 1. Between the ange Ia of bushing I0 and the plate I is inserted a gasket seal 2|. Inside of the housing 2 a spring I2 is slipped over the shaft 3 and one end rests against shoulder 4, whereas the other end presses against 5 Washer I3 which in turn forces plastic packing 20 into the recess in cup' I4 and also presses the face I6 of cup I4 against coacting face I0b of the' bushing. The cup I4 is bored out to fit over the shaft at I5 and counterbored to form 10 cavity walls I'I and I8, this produces sharp edge I9. When the plastic packing 20 is forced into position by the washer I3 it swells against the shaft 3 and against edge I 9 to form an immediate seal at this point. The cup I4 has a concave 15 face I6 which is highly polished and runs against the bushing face Illb which is also highly polished. When the shaft of the compressor is rotated the spring I2, washer I3, plastic packing 20, and the cup I4 all rotate with it; whereas bushing I0, 20 gasket 2l, plate l, gasket 9, and bolts 8 all remain stationary with the housing 2.

The faces of cup I4 and bushing I 0 coact to form the rotary seal. The face I6 of the cup v I4 is shown in its preferred form in Fig. 2; like- 25 Wise the coacting face Ib of the bushing I Il is shown in Fig. 3. The diameter of face I6 of the hardened bushing is preferably larger than the diameter of the face I0b of the soft f bushing Ill.A The purpose of this is to have the 30 harder surface which will Wear the least out or Wear away the full face of the softer bushing and leave no edge With its attendant chips and overhang. Obviously the cup and bushing can be reversed as to hardness or material, but in any 35 instance the harder must be the larger to maintain this same condition of Wear.

Whenthe seal is installed in the compressor the mechanic has no difliculty in aligning the two sealing elements as-the bushing I0 and the face 40 I6 of the cup take a definite seat against each other, 'the one permitting the other to align, as the bolts 8 are pulled up tight.

Having described the invention what is claimed as new and is desired to be secured by Letters 45 Patent is:-

l. Means for sealing a shaft passing through the wall of a housing, comprising a cup having a shouldered reces surrounding said shaft, a packing of plastic material seated in said cup, means 50 to force said packing into said cup having sufficient strength to distort said packing beyond said shoulder for frictionally retaining said cup on said shaft and forming a seal therebetween, a concave sealing face on the end of the cup, a com- 55 plementary seal element having a seal face disposed around said shaft, and shiftable laterally with respect thereto, and means for securing the seal element to the housing including an apertured disc, said seal element and disc being constructed and arranged to provide for adjustment of said seal element to secure mating contact between said seal faces. Y

2. Means for sealing a shaft passing through the wall of a housing, comprisinga cup having a recess surrounding said shaft, a packing of -plastic material seated in said recess, means to force said packing into said cup having sufficient strength to distort said packing for frictionally retaining said cup on said shaft and forming a seal therebetween, a concave sealing face on the end of the cup, a complementary seal element having va seal face disposed around said shaft and shiftable laterally with respect thereto and secured to said housing by an apertured disc,

said seal element and disc being constructed and arranged to provide for adjustment of said seal seal faces, and a backing plate to force the seal' element against the apertured disc.

3. Means for sealing a shaft passing through the wall of a housing, comprising a cup having a recess surrounding said shaft, a packing of plastic material seated i'n said recess, means to force said packing into said cup, having sucient strength to distortv said packing, for frictionally retaining said cup on said shaft and forming a seal therebetween, a sealing face on the end of the cup, a complementary seal element having a seal face disposed around said shaft, and shiftable laterally withA respect thereto and secured to ysaid housing-by an apertured disc, said seal `element and disc being constructed and arranged to provide for adjustment of said seal element to secure mating contact between said seal faces, 

